1. (Field of the Invention)
The present invention relates to an X-ray fluorescence spectrometer for quantitatively analyzing hexavalent chromium and a program for use therewith.
2. (Description of the Prior Art)
It is well known that chromium exist in various forms such as, for
example, metal chrome (zero-valent chrome), trivalent chrome and hexavalent chrome and, of those chromes, the hexavalent chrome has such a high toxicity that quantitative analysis thereof is often required separately from the other chromes.
For the quantitative analysis of the hexavalent chrome through the X-ray fluorescence analysis, a method is known, in which using an X-ray fluorescence spectrometer of a type capable of continuously monochromating (in two stages) fluorescent X-rays, emitted from a sample, by means of two spectroscopic devices, i.e., a so-called double crystal spectrometer, Cr—Kβ1 line is measured to thereby quantitatively analyze trivalent chrome and hexavalent  chrome separately. See, for example, Y. Gohshi et al, “Advances in X-ray Analysis” (USA) 1975, Vol. 18, p. 406-414.
It is also known that using the double crystal spectrometer, Cr—Kα line is measured so that trivalent chrome and hexavalent chrome can be identified in reference to the shift of a peak and the FWHM (full width at half maximum) of  the peak and the trivalent chrome and metal chrome can be identified in reference to the FWHM of the peak. See, for example, “Ni-kesshogata Koubunnkainou Keikou X-senn-hou niyoru Kagakujoutai-bunnsekihou no Hantei-genkai I (Limit I in Chemical State Analyzing Method Using Double Crystal-type High Resolution Fluorescent X-ray Technology) published May 24, 2003 at the 64-th Discussion on Analytic Chemistry.
However, in any of those known method, the use of the double crystal spectrometer is essential, which is a complicated and bulky X-ray fluorescence spectrometer. In particular, the first described prior art method is silent as to whether or not the metal chrome and the hexavalent chrome can be quantitatively analyzed separately and, on the other hand, the second described prior art method is specifically intended to determine the valence of the chrome and not to quantitatively analyze the chromes separately according to the valence and is therefore unable to quantitatively analyze the hexavalent chrome separately from any other chromes. Also, other known analytical technologies than the X-ray fluorescence analysis are based on a destructive test and/or require complicated and time-consuming analytical procedures.